I have some questions to ask about the 653/656 issue. My car was all original when i purchased it. It came with the original marchal 653's. There are no markings on the top of the light and the bulb is the smaller round type with 2 pins( twist type).I just purchased a spare set that looks the same,are 653's , but have a larger bulb. Will these three pin,12 volt lights work ok? They only have one wire coming out and the other is grounded to the reflector. Could ford have received a large order of marchals that some were 653's and some 656's? Does anyone have the same lights on their car like i have on mine? thanks rich